1. Field of the Invention
The present invention relates to a condenser of a refrigerator, and more particularly to a method of manufacturing a condenser for a refrigerator in which a heat discharging tube is attached to a heat discharging plate made of acrylonitrile-butadiene-styrene resin (hereinafter, referred to as ABS resin) to improve a heat discharging effect of the condenser, while a back portion of the refrigerator is covered with the heat discharging plate to improve an external appearance.
2. Description of the Prior Art
In general, a refrigerator typically includes a compressor for compressing an evaporated refrigerant, a condenser for absorbing heat from a compressed refrigerant and discharging the heat to the atmosphere so that the refrigerant can be liquefied, an expansion valve for reducing a pressure of the Uquefied refrigerant and expanding the refrigerant, and an evaporator for absorbing heat from the air of a room and evaporating the refrigerant. The devices are connected to each other by means of pipes which create a refrigerant pathway. The refrigerant undergoes phase changes while being repeatedly circulated through the pipes connecting the devices of the air conditioner to each other, thereby absorbing the heat from inner spaces of the refrigerator and discharging the heat to the atmosphere.
A refrigerating ability of the refrigerator is affected by an amount of the heat discharged from the condenser. The condenser of the refrigerator generally is disposed at a back portion of the refrigerator, where a refrigerant tube is attached to an expanded metal in one case and is sandwiched between two sheets of the expanded metal in another case. However, the expanded metal is a poor choice for a fin since the radio of material to an exposed surface is quite now.
U.S. Pat. No. 5,398,752 (issued to Roy W. Abbott on Mar. 21, 1995) discloses a lower cost method of manufacturing a louvered strip fin sheet and a heat exchanger 10 having a minimum strip fin of minimum depth to maximize a heat transfer of an air side.
FIG. 1 is a perspective view showing a method of lancing sheet material 22 into parallel rows of strip fins 24 by means of rotary cutters 20 according to Abbott's patient. FIG. 2 is perspective view showing an alternate method of lancing the sheet material 22 and shearing to a desired length by means of a punch and die set 26. FIG. 3 is a plan view of desired width and length of a completed heat exchanger 10, a side view of a serpentined tube 40 sandwiched between lanced sheets 28, and an expanded view of joints 42 between the serpentined tube 40 and unlanced strips 30 located between rows of lanced strip fins 24. As shown in FIG. 1, a roll of sheet stock 22 is pulled through a pair of rotary stock cutters 20 having cutting teeth which lance parallel rows of strip fins 24 separated by narrow unlanced strips 30 and edges 32 in lanced sheets 28. An alternate method is shown in FIG. 2. In FIG. 2, the punch and die 26 forms strip fins 24 in a sheet. In FIGS. 1 and 2, the combination of the punch and the die 26, or multiple lance cutting rolls 20 forms lanced sheets 28 as best shown in FIG. 3. A preformed tube assembly 40 can be seam welded, overlapping spot welded, laser welded, copper brazed, soldered, or adhesive bonded to steel and alloy lanced sheets; or laser seam welded, oven brazed, dip brazed, vacuum brazed, or adhesive bonded to aluminum, copper, and alloy lanced sheets to form the heat exchanger 10. As shown FIG. 3, the heat exchanger 10 is formed by joining lanced sheets 28 to the preformed tube 40 resulting in a double layer of strip fin sheet material due to overlapping a sheet of the unlanced strip 30 over the tubing 40 at the joints 42.
The heat exchanger 10 made in this concept allows independent selection of tube wall thickness and fin thickness. The tube wall thickness can be selected to meet any desired pressure containment specification while the fin thickness can be selected independently according to optimization of heat transfer, rigidity, and economical considerations.
In the method of manufacturing the strip fin sheet and the heat exchanger 10 according to the Abbott's patent, however, the stock cutters 20 or the combination of the punch and the die 26 lance the sheets and cut the lanced sheets 28 to a desired size. After that, the tube 40 is disposed between the two sheets and joints 42 between an unlanced portion of the sheets and the tube 40 must be welded or bonded by adhesive.
Accordingly, there is disadvantages in that a process for manufacturing the heat exchanger is complicated and it is difficult to weld or bond the tube to the sheets.